squares = [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
def ou(x):
    return x%2==0
# 挑选偶数
# ll = filter(ou,squares)


# if __name__=="__main__":
#     ll = filter(lambda x: x % 2 == 1, squares)
#     print(list(ll))